Instrumentation and analysis have been developed for the measurement of ionic currents in the bovine chromaffin cell using whole cell and single channel recording. Instrumentation includes a current-to-voltage converter, an AT microcomputer system, a PACE computer system, voltage stimulator, filter, and threshold detector. Measurements of event durations and event amplitudes for different membrane potentials and appropriate inhibitory drugs (example: muscarine) were performed on the collected data. The events were collated and then fit to appropriate functions that characterized the population.